Yes, you should get it.

MammogramThe American Cancer Society (ACS) recommends yearly mammograms beginning at age 40, but the U.S. Preventive Services Task Force (USPSTF) endorses waiting another decade and then getting one only every other year to avoid the risk of unnecessary biopsies. If you're younger than 40 and at high risk, check with your doc.

Pap SmearThe annual Pap is history. Instead, get one every three years, starting at age 21. At 30, you can go five years with a Pap plus an HPV test. In your 20s, HPV is very common, and likely to go away on its own, so the test isn't needed then, says Virginia Moyer, M.D., chair of the USPSTF.

ColonoscopyNo one wants a colonoscopy, but research shows it can lower the risk of developing colon cancer by 77 percent. You don't need to get your first until age 50; then every 10 years after that. If you're younger than 50 and at high risk, your doctor might want to get a head start.

You can probably skip it.

Home Genetic TestsThese kits claim that with a saliva sample, you can know your genetic cancer risk. But the science is still evolving. "Testing positive doesn't mean you'll get cancer, and testing negative doesn't mean you won't," says Muin J. Khoury, M.D., director of the Office of Public Health Genomics at the Centers for Disease Control and Prevention.

Lung CTYou need to consider this only if you're older than 55 and have a history of pack-a-day smoking for at least 30 years. Not you? Even if you're a smoker, screening isn't recommended—there's a large chance of false positives as well as medical complications due to unnecessary diagnostic procedures. If you have a persistent cough, see your doc.

Maybe. You might want it.

Breast Self-ExamIt's unlikely you'll find cancer during a self-exam, Dr. Moyer says. In fact, you're more likely to find a cancerous lump while randomly soaping up in the shower. That said, do regular checks if they make you feel at ease.

Clinical Breast ExamSurprisingly, the USPSTF does not recommend breast exams, saying the evidence isn't strong enough to prove that this mainstay helps find cancer. The ACS feels differently. Its official recommendation: Women in their 20s and 30s should get an exam about every three years, typically during checkups with their ob/gyn. After age 40, go once a year.

Skin CheckDon't cancel your freckle check—we still want you to get one! The USPSTF and the ACS say the evidence that skin checks reduce cancer deaths isn't strong enough to warrant official recommendations. But that doesn't mean they're a bad idea. The American Academy of Dermatologysuggests that you have a derm give you a head-to-toe once-over for suspicious moles. After your first check, your doctor will tell you how often to come back.

Thyroid CheckThe major cancer organizations have yet to issue official guidelines on routine thyroid screening. But the American Association of Clinical Endocrinologists recommends that doctors do neck checks during physicals to feel for nodules or changes to the gland. Blood tests or thyroid ultrasounds are not recommended unless a thyroid exam turns up something suspicious or you have a family history.